Had some programming session on working with hfsprogs's packaging for Debian. I finally saw how to build a multi-arch building and introduced some cruft to compile it under amd64 (aka, x86-64), since Apple's code is not 64-bit clean. Ugh!
And that's because they have the guts to show us their source code. Imagine what a disaster it is to see proprietary software that is completely closed!